Process of covering metallic objects with an electroplating of magnetic oxide of iron



Unit dramas PATIENT rricn,

WVILLIAM H. \VINSLOIV, OF BROOKLYN, NEW YORK.

PROCESS OF COVERING METALLIC OBJECTS WITH AN ELECIROPLAIING 0F MAGNETICOXlDlE OF IRON.

$PECIFICATION forming part of Letters Patent No. 331,104, dated November24, 1885.

Application filed June 2, 1884. Serial No. 133,617.

To aZZ whom it may concern.-

Be it known that 1, WILLIAM H. WINs- LOW, a citizen of the UnitedStates, residing at Brooklyn, in the county of Kings and State of NewYork, have invented a certain new and useful Improvement in the Art ofCovering Metallic Objects with an Electroplated Coat of Magnetic Oxideof Iron; and I do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same.

My invention consists of the art of covering metallic objects with anelectroplatedcoat of magnetic oxide of iron by first electroplating themetallic object with iron in the ordinary way, and then converting theelectro-deposit of iron into magnetic oxide of iron, one way ofaccomplishing which is to subject the iron-plated object to anatmosphere of superheated steam.

In order that my invention may be clearly understood, I will proceed todescribe it as applied to a copper electrotype. For iron plating such anelectrotype, I have used with very satisfactory results a bath preparedfrom a solution of twenty (20) parts of salammoniacin one hundred (100)parts of wa ter electrolized by the use of two wroughtiron plates foranode and cathode, respectively. The point of proper saturation of thebath having been reached, which may be ascertained by the ordinary testmethod, the

- iron cathodeis removed, and the copper electrotype put in its place.The electrotype becomes rapidly covered with a deposit of iron. Theplating must be carefully con ducted, in order that the deposit may bebright and as smooth as the surface of the electrotype, because thebeauty of the finish attained by the conversion of the deposited ironcoat into magnetic oxide of iron de pends largely on the character ofthe pre liminary plating. I find that about an hours suspension in thisloath produces a thick enough film of iron on the surface of theelectrotype to serve the purpose of the final operation. The iron-coatedelectrotype is (No specimens.)

then introduced into a fireproof muffle filled with an atmosphere ofsuperheated steam at a temperature of from 1000 to 12:00 Fahrenheit. Anexposure to this steam atmosphere of from five to seven minutes convertsthe iron coat on the surface of the electrotype into magnetic oxide ofiron. Care must be exercised to so time the exposure to the steamatmosphere that the iron coat only is converted. If the exposure becontinued too long, the surface of the copper beneath the iron will beoxidized also, as a consequence of which the magnetic-oxideof-iron coator plating will lose its hold on the copper and can be rubbed offeasily.

The magneticoxide-of-iron plating thus produced is very coherent, andhas a steelbluish black color, very attractive to the eye. Its hard andnon-corrosive qualities are well known.

My invention of the art of producing a magnetic-oxide-of-iron plating isnot limited to the particular bath described, since other knowniron-plating baths may be used; nor to the described means of convertingthe iron plating'into magnetic oxide, because the conversion may beeffected by other known means-for instance, by the use of what is knownas the Bower- Earff Furnace.

My invention is applicable to all articles of manufacture and objects ofart in metals that are susceptible of being coated with anelectro-deposit of iron, which can afterward be converted into magneticoxide without injury to the article itself.

I am aware that metallic objectsletterpress electrotypes, forinstancehave here tofore been plated with iron or steel; also, thatobjects of iron have heretofore been provided with a coating of magneticoxide by a direct conversion of the surface of the iron object. I amalso aware of the United States Patent No. 106,823; but I believe that Iam the first to have covered metallic objeots with an electroplated coatof magnetic oxide of iron.

The resultant article of my described process is claimed in myapplication fora United States Patentvfiled April 30, 1885, Serial No.In testimony whereof Iaffix my signature in 10 164,024. presence of twowitnesses.

I claim as my invention The art of covering a metallic object withWILLIAM H. WIN SLOW.

5 an e1ectrop1ated coat of magnetic oxide of iron, which consists infirst electroplating Witnesses: the object with iron and then convertingthe MICHAEL EGER, plating of iron into magnetic oxide, substan- GEORGEE. HORNUNN. tially as before set forth.

